public class MyQueue {
    static class ListNode{
        public ListNode first;
        public ListNode next;
        public int val;

        public ListNode(int val) {
            this.val = val;
        }
    }
    public ListNode first;
    public ListNode last;
    public void offer(int val){

    }
    /*public int poll(){

    }
    public int peek(){

    }*/
    public int size(){
        ListNode cur = first;
        int count = 0;
        while(cur != null){
            cur = cur.next;
            count++;
        }
        return count;
    }
    public boolean empty(){
        if(first == null){
            return true;
        }
        return false;
    }
}
